The invention relates to improvements in apparatus for supporting and guiding continuously advancing cigarette rods, cigar rods, cigarillo rods, filter rods, hollow rods (tubes) and/or other rod-shaped products of the tobacco processing industry. More particularly, the invention relates to improvements in apparatus for supporting and guiding an advancing rod during severing by the knife or knives of a severing apparatus. Severing apparatus of the above outlined character, and apparatus for supporting and guiding the advancing rod during severing, are used in cigarette rod making machines, cigar rod making machines, cigarillo rod making machines and filter rod or filter tube making machines.
The following description of the invention will deal primarily with the guidance and severing of cigarette rods in cigarette rod making machines, e.g., in machines of the type known as PROTOS which are distributed by the assignee of the present application. It is to be understood, however, that similar or identical apparatus can be used with equal advantage in cigarillo, cigar or filter making machines.
The severing apparatus (called cut-off) of a cigarette rod making machine is used to subdivide a continuously advancing cigarette rod into plain cigarettes of unit length or multiple unit length. Such cigarettes can be delivered to storage or are transported directly into a packing or filter tipping machine. Since a cigarette rod is relatively soft, it must be adequately supported during severing by an orbiting knife which serves to cut across the rod several thousand times per minute while the rod advances at a speed of several hundred meters per minute. The means for supporting the rod at the severing station normally comprises a tubular guide with a slot or gap for the knife which forms part of the cut-off The guide preferably serves as a counterknife and cooperates with the orbiting knife of the cut-off to ensure the making of clean cuts across the rapidly advancing rod. Moreover, and since the knife should sever the advancing rod in a plane which is normal to the axis of the rod, it is necessary to move the knife with and at the exact speed of the rod each time the knife is in the process of severing the rod. The same applies for the rod supporting guide In other words, the knife carrier of the cut-off must be mounted to carry out alternating forward and rearward movements in and counter to the direction of advancement of the rod, and the same holds true for the guide. The rod is severed each time the knife carrier and the guide move in the direction of advancement of the rod and at the same speed, namely at the speed of advancement of the rod in the cigarette rod making machine.
Apparatus of the above outlined character are well known in the tobacco processing industry. Reference may be had to U.S. Pat. Nos. 3,140,632 to Rowlands et al., 3,168,848 to Bardenhagen et al., 3,215,178 to Bardenhagen, 3,476,002 to Bardenhagen et al., 3,815,460 to Bardenhagen and 3,830,126 to Ringe.